Reversing valve for a diaphragm pump

ABSTRACT

A valve arrangement including a valve housing ( 10 ) which includes an inlet port ( 11 ) and two outlet ports ( 12, 13 ) for fluid flowing through the housing. A valve element ( 15 ) is accommodated in a first valve space in the valve housing and movable between two end positions. The valve element includes two surfaces ( 16 ), each of which is adapted for co-action with a respective outlet port such as to close an associated outlet port in one and the other of the end positions of the valve element ( 15 ). A device ( 20  or  21  and  26, 47 ) for resetting the valve element between the positions. The valve element ( 15 ) is mounted on one end of a pivotal arm ( 18 ) and has the form of a valve plate or disc which includes valve-element surfaces ( 16 ) for alternate co-action with a respective outlet port ( 12, 13 ). The arm ( 18 ) carrying the valve element ( 15 ) is connected mechanically to and adapted to drive a further valve element ( 42 ), which is accommodated in a separate, second valve space, between two positions in which the further valve element connects one or the other of two fluid inlet ports ( 43 ) to a fluid outlet port ( 45 ) which is common to the fluid inlet ports.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to REVERSING VALVE FOR A DIAPHRAGM PUMP toSvante Bahrton, Ser. No. 09/530,590 filed May 5, 2000.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a valve arrangement of the kind thatincludes a valve housing which has an inlet port and two outlet portsfor fluid flowing through the housing. The valve housing includes afirst valve chamber which accommodates a valve element that can movebetween two end positions and that has two surfaces which each co-actwith a respective outlet port and which function to close an associatedoutlet port in respective first and second end positions of the valveelements. The valve arrangement further including means for switchingthe valve element between the positions and the valve element beingmounted on one end of a pivotal arm.

2. Related Art

Valve arrangements of this kind are known, for instance, from EP 0 492242.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a novel and improvedvalve arrangement chat comprises removable parts, and which can be resetquickly and positively and which will not become adjusted to a neutralposition in which both of said output ports communicate permanently withthe inlet port at one and the same time.

It is proposed to this end in accordance with the invention that thevalve element of a valve arrangement of the aforedescribed kind shall begiven the form of a valve plate or valve disc that has mutually oppositea valve element surfaces disposed for alternate co-action with arespective outlet port; and in that the arm carrying said valve elementis coupled mechanically to a further valve element accommodated in aseparate, second valve chamber such as to drive said further valveelement between two positions in which said element connects one or theother of two fluid inlet ports to a fluid outlet port which is common tosaid two fluid inlet ports. This arrangement provides an improved valvearrangement with the aid of simple means.

Further characteristic features of the invention will be apparent fromthe following wherein an object of the invention is to provide that thepivotal arm extends into the further valve space and carries the furthervalve element at a second end located within the further valve space,wherewith the further valve element also has the form of a valve platewhich includes mutually opposite valve-element surfaces for co-actionwith a respective associated inlet port.

Another object of the invention is to provide that the valve arrangementis co-ordinated with a double-acting pump which includes two spaceshaving valve-controlled respective inlets and outlets for a gaseousdrive fluid and a liquid working fluid transported by the pump,wherewith the spaces are divided into an operating chamber and a workingchamber by means of a movable partition wall in the form of a diaphragm,in that a device for transferring movement of one partition wall to theother partition wall, and vice versa, extends between the movablepartition walls, and in that each of the operating-chamber inlets iscoupled to its respective outlet port associated with the first valvespace of the valve arrangement, and each operating chamber outlet isconnected to its respective fluid inlet port associated with the secondvalve space.

A still further object of the invention is to provide that the eachoperating chamber is connected to its respective outlet port of thevalve arrangement via a conduit which is adapted to be closed by theassociated partition wall immediately prior to the commencement of aworking stroke of the partition wall, and in that a fluid bleedpassageway extends between the outlet ports and the inlet port common tothe outlet ports.

Another object of the invention is to provide that each of the bleedpassageways is comprised of a bore or channel that extends through thematerial of the valve housing or through associated valve element.

An object of the invention is to provide that the partition wallsinclude bellow-like structures which are open to the conduits and whichfunction to generate an over pressure in an associated conduit whenclosing the conduit.

A still further object of the invention is to provide that the operatingchambers are located close together on both sides of the valvearrangement, and in that the partition walls are provided with pinswhich each extend into a respective outlet port and, when the partitionwalls are in their inner end positions, act on an associatedvalve-element surface so as to reset the valve element.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

Also from the following description of a number of chosen, exemplifyingembodiments of the novel valve arrangement illustrated in theaccompanying drawings.

FIG. 1 is a highly schematic, sectional view of a first embodiment of aninventive valve arrangement combined with a double-acting pump.

FIG. 2 is a sectional view similar to FIG. 1, but with a modifiedresetting means.

FIG. 3 is a sectional view similar to FIG. 1 which shows a differentlydesigned double-acting pump whose pump housing accommodates an inventivevalve arrangement which includes a further modified resetting means.

FIG. 4 is a sectional view similar to FIG. 1 and shows yet anothermodified version of the resetting means.

FIG. 5 is a sectional view similar to FIG. 1, which show two bleedpassageways.

DESCRIPTION OF THE INVENTION

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

Valve components that find correspondence or general correspondence inthe different Figures of the drawings have been identified with the samereference signs.

The valve arrangement illustrated in FIG. 1 comprises a valve housing 10which includes an inlet port 11 and two outlet ports 12, 13 for fluid,either gaseous or liquid, flowing through the valve housing. The fluidis delivered at an overpressure from a source (not shown), as indicatedby arrow 14. The valve housing 10 accommodates a movable valve element15 which has mutually opposite surfaces 16 for closing an associatedoutlet port 12 or 13 in a respective one or the other of two endpositions of the valve element 15. The orifices of respective outletports are surrounded by sealing rings 17, to facilitate sealed closureof the valve. The valve element 15 is comprised of a valve plate orvalve disc, the mutually opposite sides of which form closing surfaces16 and which is mounted on one end of a movable arm 18. The arm 18 ismounted in the valve housing 10 at 19 for pivotal movement between saidend positions, wherewith the surfaces 16 of said valve element close oneor the other of said outlet ports 12, 13. However, it lies within thescope of the invention to provide the valve-element surfaces on a valveelement which has a different form than the illustrated valve element,for instance a substantially spherical form. In the illustrated case,the fluid entering through the inlet port 11 passes through the valvehousing 10 and out through the open outlet port 12. The closed outletport 13 is not placed under pressure and consequently the valve element15 will be held pressed against the port 13 by the force exerted by theinflowing fluid.

In the FIGS. 1 and 5 embodiments, the valve element 15 has extendingtherethrough a bleed passageway or opening 20 whose area is so smallthat the flow of medium through the passageway or opening 20 will beessentially negligible in relation to the total flow through the valvehousing 10. The bleed passageway or bleed opening 20 can be replacedwith, e.g., two bleed passageways (shown at 21 in FIG. 5 that extendbetween the inlet port 11 and a respective one of the outlet ports 12,13. The valve arrangement is reset by closure means 26, 47 which areadapted to stop temporarily all flow of fluid through an associatedoutlet port. The means being described in more detail below. The closuremeans 26, 47 and the bleed passageways 21 or the bleed opening 20 thusform a valve resetting means. Switching of the valve from theillustrated valve mode or state in which the fluid passes in through theport 11 and out through the port 12 is effected by virtue of the closuremeans 26, 47 shown to the right in FIGS. 1 and 5 becoming active so asto build-up a static fluid pressure in the port 13 via a conduit 41, asa result of the presence of the bleed opening or bleed passageways 20,21. The static fluid pressure generating on the surface of the valveelement 15 facing towards the port 13 a force that exceeds the pressureexerted on the opposite surface of the valve element by the fluidflowing through the valve housing 10. The differential pressure createdby the fluid flow therewith swings the valve element 15 rapidly awayfrom the position in which it seals the port 13 and further, until itreaches the position in which it seals the outlet port 12, so that fluidwill now exit through the port 13 as soon as the closure device 26, 47shown on the right of FIGS. 1 and 5 has returned to the position inwhich the port 13 is open.

FIG. 1 shows an inventive valve arrangement connected for controllingthe operation of a double-acting diaphragm pump. The pump includes agenerally cylindrical pump housing 23 which includes two spaces that aredelimited by the end walls 24 of the housing and internal walls 25. Eachof these spaces is, in turn, divided into a working chamber 27 and anoperating chamber 28 by means of a respective diaphragm unit 26, saidworking chambers 27 being located close to one another and saidoperating chambers being located outwardly of their associated diaphragmunit 26. Each of the working chambers 27 has valve-controlled inlets andoutlets 29, 30 for working fluid transported by the pump, preferably aliquid working fluid. In the illustrated embodiment, the inlets andoutlets 29, 30 have the form of openings in the inner chamber walls 25and check valves 31 in the form of flap valves co-acting with saidopenings. The working fluid arrives to a space 33 in the pump locatedbetween the walls 25, in the direction indicated by arrow 32, and leavesthe pump through a diametrically opposite space 34 which is also locatedbetween the walls 25, and exits said space 34 in the direction of arrow35.

The diaphragm units 26 include a round, relatively rigid central part36, and a peripheral part 37 which is comprised of a relatively pliablematerial and which is connected to the pump housing 23 at its radiallyouter edge. The diaphragm units 26 are connected to one another by meansof a rod 38 which transfers the movement of one diaphragm unit to theother, and vice versa. For instance, when the diaphragm unit 26 on theleft in FIG. 1 moves to the right in response to pressurized operatingfluid or drive fluid, e.g. compressed air, in the left operating chamber28, the rod 38 will press the right diaphragm unit 26 to the right asseen in the FIG.1.

The operating chambers 28 are provided at 39 and 40 with openings thatserve as drive-fluid inlets and outlets respectively, wherewith theinlets 39 are connected via conduits 41 and the valve arrangement 10, toa pressurized fluid source, e.g. to a compressed air network. Inaddition to the valve element 15 mounted at 19 on the arm 18, the valvearrangement includes a further valve element 42 in the form of a valveplate or valve disc mounted on the other end of the arm 18, said arm 18being pivotally mounted between its ends in the case of the illustratedembodiment. The further valve element 42 is accommodated in avalve-housing space or room that is separated from the inlet and outletports 11-13 in a gas-tight and liquid-tight manner and the mutuallyopposite sides of said valve element close one or the other of two inletports 43 arranged in the valve housing 10 and intended for return fluidfrom the operating chambers 28. The latter are connected to the ports 43via the outlets 40 and conduits 44. The area of the ports 43 is smallerthan the area of the ports 12, 13 and said ports 43, in turn,communicate with an outlet port 45 for return fluid, depending on theposition of the valve element 42, said return fluid leaving the valvehousing 10 in the manner indicated by arrow 46. The valve element 42 isreset by means of the valve element 15 and the arm 18 in a manner suchas to establish communication between the operating chamber 28 and theoutlet port 45 to the right in FIG. 1, provided that there iscommunication between the operating chamber 28 on the left of FIG. 1 andthe operating-fluid inlet port 11 of the valve arrangement, whereascommunication between the operating chamber 28 on the left in FIG. 1 andthe outlet port 45 will be established provided that the operatingchamber 28 on the right of FIG. 1 communicates with the inlet port 11 ofthe valve arrangement.

Disposed around the operating fluid inlets 40 are seals 47 with whichthe central parts 36 of the diaphragm units are brought into sealingcontact when said diaphragm units 26 reach their outer positions, asillustrated on the right in FIG. 1.

The valve arrangement illustrated in FIG. 1 operates in the followingmanner: The pressurized drive fluid or operating fluid passes to theleft operating chamber 28, through the inlet port 11, the outlet port 12and the conduit 41 connected thereto. The outlet port 43 on the left inFIG. 1 is held closed by means of the force exerted by the incomingdrive fluid on the valve element 15. The left diaphragm unit 26 ispressed to the right and therewith also presses the right diaphragm unit26 to the right in FIG. 1, through the medium of the rod 38. Workingfluid is therewith pressed out from the left working chamber 27, throughthe open outlet 30, and is sucked into the right working chamber 27through the open inlet 29, while drive fluid departs through the outlet40, the conduit 44 and the port 45 of the right operating chamber 28.When the central part 36 of the right diaphragm unit 26 has reached itsend position and seals against the sealing ring 47 around the rightinlet conduit 41, there is built-up by the drive fluid entering the port13 through its associated bleed passageway 20 or 21 a static overpressure which automatically resets the valve element 15 of the valvearrangement in the aforedescribed way. The flow through the pump andvalve arrangement will therewith be reversed, i.e. drive fluid will bepressed through the port 13 and into the operating chamber 23 on theright of FIG. 1 and will leave through the left operating chamber,whereas working fluid will be pressed out from the right working chamber27 and sucked into the left working chamber until the left diaphragmunit 26 reaches its outer end position and therewith automaticallyresets the valve element 15.

The arrangement illustrated in FIG. 2 is similar to the arrangementillustrated in FIG. 1 and will be described solely with reference tothose respects in which it differs from the FIG. 1 embodiment. Thedifference resides in the ability to avoid the use of bleed passageways,such as the passageways 20 or 21, so that all drive fluid enteringthrough the inlet port 11 can be used for useful work. In order togenerate a force that will balance out the force exerted by the flowingworking fluid on the valve element 15 and also the small force exertedby the flow of return fluid on the valve element 42, the outer sides ofthe partition walls 26 are provided with bellows-like structures 48 thatopen towards a respective pump end-wall 24. These bellows likestructures sealingly abut respective end-walls around the inlet 40 inthe proximity of the end positions of the partition walls 26 and pressused drive fluid through the conduit 41 connected to said inlet, so asto generate a valve-resetting pressure in that inlet port 12, 13 that isnot at the moment in use, i.e. the port 13 in the state of the pumpshown in FIG. 2.

In the arrangement illustrated in FIG. 3, the double-acting pump is ofthe kind where the working chambers 27 are located proximal to theend-walls 24 of the pump housing and where the flow of medium throughsaid chambers is controlled by ball valves 31. The operating chambers 23are thus located close to one another on opposite sides of a centralpump-housing part 49 which includes a valve arrangement of theconstruction shown in FIG. 2. Resetting of the valve element 15, andtherewith also of the valve element 42, however, is initiatedmechanically. The mutually facing sides of the central parts 36 of thepartition walls 26 are provided to this end with pins 50 which extendaxially into a respective outlet port 12, 13. The length of the pins isadapted so that when the partition walls 26 occupy their innerpositions, the pins 50 will press the valve element 15 slightly awayfrom the position in which one of the mutually opposite surfaces 16 ofsaid valve element closes an outlet port, either port 12 or port 13, soas to thereafter reset the valve element 15 under the influence of thefluid flow through the valve arrangement, and therewith close the otheroutlet port.

The arrangement illustrated in FIG. 4 coincides with the arrangementillustrated in FIG. 1 except in the following respects: The bleedpassageways 21 of the FIG. 1 arrangement have been replaced in the FIG.4 arrangement with a balancing valve system that includes two valves 51.The valves 51 are connected to a pressurized fluid network 52, suitablythe same network as that which delivers drive fluid to the inlet port11. Each of the valves can be connected to a respective drive-fluidconduit 41, and therewith to a respective port 12, 13, via conduits 53.The valves 51 are two-position valves which are spring biased towards anormal mode or state in which the connection between the network 52 andthe conduits 53 is broken, but which can be set against the action ofsaid spring force to an active mode or state in which connection betweennetwork 52 and conduit 53 is established. To enable resetting orswitching of the valves to be achieved, each of the valves includes arespective pin 54. Each of the pins 54 projects into its respectivechamber 28 and, as it engages a partition wall 26 approaching its outerend position, switches the valve concerned to its active state. In FIG.4, the left valve 54 is in its normal state, or rest mode, in whichconnection between the network 52 and the conduit 53 is broken, whereasthe right valve 51has been switched to its active state or mode as aresult of the partition wall 36 acting on the pin 54, wherewith theoutlet port 13 is connected to the compressed air network 52 via theright valve 51 and the conduits 53 and 41. There is then generatedbriefly in port 13 an over pressure which causes resetting of the valveelement 15, therewith causing the partition walls 26 to move to the leftin FIG. 4 and enabling the valve 51 to return to its rest mode.

It will be understood that the invention is not restricted to theaforedescribed and illustrated exemplifying embodiments thereof and thatmodifications can be made within the scope of the inventive concept asdefined in the Claims. For instance, movement of the valve element fromone or the other of its closing positions can be initiatedelectromagnetically and the conduits 53 of the embodiment illustrated inFIG. 4 may open into associated operating chambers 28. Similarly, thepins 54 may be attached to associated partition walls 26 and mounted foraxial movement in the nearby pump end-wall, for resetting the valves 51in the outer end positions of respective partition walls 26. Themovement transferring device 38 connected to the partition walls 26 maybe sprung in the direction of its longitudinal axis, for instance in themanner shown in WO 96/34201, wherewith the operating chambers 28 mayalso be placed under pressure simultaneously for short periods of time,so as to avoid pulsations in the pumped working medium. The build-up ofpressure in the port 12 or the port 13 may be controlled with the aid ofthrottle check valves in the conduits 41.

It will be understood that for reasons of clarity, the valve arrangementillustrated in FIGS. 1-4 has been greatly enlarged in relation to thedouble-acting pump. However, the valve arrangement may be constructedfor all manner of gas or liquid flows, i.e. from very small to verylarge fluid flows, and the term liquid shall be understood to alsoinclude fluid/solids dispersions and slurries.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and, accordingly, all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention.

What is claimed is:
 1. A valve arrangement comprising a valve housingthat includes an inlet port and two respective outlet ports for fluidpassing through the housing, a valve element which is accommodated in afirst valve space in the valve housing and movable between two endpositions and which includes two mutually opposite surfaces, each ofwhich is adapted for co-action with said outlet port such as to closesaid outlet port in a respective one and the other of the two endpositions of said valve element, and resetting means for resetting saidvalve element between said positions, said valve element being mountedon one end of a pivotal arm, said valve element having a valve platewhich includes mutually opposite surfaces for alternate co-action withsaid respective outlet port; and said pivotal arm carrying said valveelement and connected mechanically to drive a further valve elementaccommodated in a separate, second valve space, said further valveelement being driven between two positions in which it connects eitherone or the other of further two fluid inlet ports to a further fluidoutlet port which is common to said further two inlet ports.
 2. Thevalve arrangement according to claim 1, wherein said pivotal arm extendsinto the second valve space and carries the further valve element at asecond end located within said second valve space, wherewith saidfurther valve element is a valve plate which includes mutually oppositevalve-element surfaces for co-action with a respective associated inletport.
 3. The valve arrangement according to claim 1, wherein said valvearrangement is co-ordinated with a double-acting pump which includes twospaces having valve-controlled respective inlets and outlets for agaseous drive fluid and a liquid working fluid transported by the pump,wherewith said spaces are divided into an operating chamber and aworking chamber by means of a movable partition wall in the form of adiaphragm; in that a device for transferring movement of one partitionwall to the other partition wall, and vice versa, extends between saidmovable partition walls, and in that each of the operating-chamberinlets is coupled to its respective outlet port associated with thefirst valve space of said valve arrangement, and each operating chamberoutlet is connected to its respective fluid inlet port associated withsaid second valve space.
 4. The valve arrangement according to claim 3,wherein said each operating chamber is connected to its respectiveoutlet port of the valve arrangement via a conduit which is adapted tobe closed by the associated partition wall immediately prior to thecommencement of a working stroke of said partition wall; and in that afluid bleed opening extends between the outlet ports and the inlet portcommon to said outlet ports.
 5. The valve arrangement according to claim4, wherein said each of the bleed openings is comprised of a bore orchannel that extends through the material of the valve housing orthrough associated valve element.
 6. The valve arrangement according toclaim 4, wherein said partition walls include bellow-like structureswhich are open to said conduits and which function to generate an overpressure in an associated conduit when closing said conduit.
 7. Thevalve arrangement according to claim 3, wherein said operating chambersare located close together on both sides of the valve arrangement, andin that the partition walls are provided with pins which each extendinto a respective outlet port and, when the partition walls are in theirinner end positions, act on an associated valve-element surface so as toreset the valve element.
 8. The valve arrangement according to claim 1,wherein said pivotal arm extends into the second valve space and carriesthe further valve element at a second end located within said secondvalve space, wherewith said further valve element is a valve disc whichincludes mutually opposite valve-element surfaces for co-action with arespective associated inlet port.
 9. The valve arrangement according toclaim 3, wherein said each operating chamber is connected to itsrespective outlet port of the valve arrangement via a conduit which isadapted to be closed by the associated partition wall immediately priorto the commencement of a working stroke of said partition wall; and inthat a fluid bleed passageway extends between the outlet ports and theinlet port common to said outlet ports.
 10. The valve arrangementaccording to claim 9, wherein said each of the bleed passageways iscomprised of a bore or channel that extends through the material of thevalve housing or through associated valve element.
 11. A valvearrangement comprising a valve housing that includes a first inlet portand two respective first outlet ports for fluid passing through thehousing, a first valve element which is accommodated in a first valvespace in the valve housing and movable between two end positions andwhich includes two mutually opposite surfaces, each of which is adaptedfor co-action with said first outlet port to close said first outletport in a respective one and the other of the two end positions of saidfirst valve element, and resetting means for resetting said first valveelement between said positions, said first valve element being mountedon one end of a pivotal arm, said first valve element having a valvedisc which includes mutually opposite surfaces for alternate co-actionwith said respective outlet port; and said pivotal arm carrying saidfirst valve element and connected mechanically to drive a second valveelement accommodated in a separate, second valve space, said secondvalve element being driven between two positions in which it connectseither one or the other of two second fluid inlet ports to a secondfluid outlet port which is common to said two second inlet ports. 12.The valve arrangement according to claim 11, wherein said pivotal armextends into the second valve space and carries the second valve elementat a second end located within said second valve space, wherewith saidsecond valve element is a valve disc which includes mutually oppositevalve-element surfaces for co-action with a respective associated inletport.
 13. The valve arrangement according to claim 12, wherein saidpivotal arm extends into the second valve space and carries the secondvalve element at a second end located within said second valve space,wherewith said second valve element also is a valve plate which includesmutually opposite valve-element surfaces for co-action with a respectiveassociated inlet port.
 14. The valve arrangement according to claim 11,wherein a fluid bleed opening extends between the outlet ports and theinlet port common to said outlet ports.
 15. The valve arrangementaccording to claim 14, wherein said each of the bleed openings iscomprised of a bore or channel that extends through the material of thevalve housing or through associated valve element.
 16. The valvearrangement according to claim 11, wherein a fluid bleed passagewayextends between the outlet ports and the inlet port common to saidoutlet ports.
 17. The valve arrangement according to claim 16, whereinsaid each of the bleed passageways is comprised of a bore or channelthat extends through the material of the valve housing or throughassociated valve element.